Underreamer for wells



April 30, 1929. w P, RUDKIN 1,710,998

- UNDER REAMER FOR WELLS Filed June 4, 1927 2 Sheets-Sheet l April 30, 1929. w. P. RUDKIN 1,710,998

I UNDER REAMER FOR WELLS Filed June 4, 927 v 2 Sheets-Sheet 2 the projection of the cutters or reamers into PATENT ounce.

WILLIAM'P. RUDKIN, OF OKLAHOMA CITY, OKLAHOMA UNDERREAMER FOR TELLS.

Application filed me 4, 1927. Serial No. 196,559.

' This invention relatesto an under-reamer for wells, and particularly to a construction embodying expansible cutters disposed to enlarge the well diameter at its lower portion.

In the drilling of oil wells it frequently occurs that a proper flow is not secured owing to the lack of gas pressure or the flow of oil from the strata into which the well extends so that it is necessary to excavate a chamber within the oil bearing strata in order to insure a proper flow of the oil. By this method a well which is not commercially productive may be brought to a proper flow and rendered valuable without the necessity of the use of explosives which often so rupture the surrounding rock and strata as to cause a flow of water into the Well and the most desirable results are secured by the formation of a chamher at, the base of the well.

The formation of such a chamber involves a position approximately transverse to the axis of the well or the body of the tool, and this is most efliciently accomplished by a link connection between the cutters and a part engaging the base of the well. In-the use of such a connection, when the links are in a folded or closed position they are practically upon a deadcenter and it is very difiicult to initiate the outward swing of the cutters so I that their movement mayJoe continued by the link members. To overcome these objections I have provided a we'dgedike member disposed to engage the free ends of the pivoted cutters which initiates their outward movement, and such movement is continued by the links.

In order that these links may expand the cutters into a substantially horizontal position and thus retain them for the reaming action, they are provided with a novel pivotal connection permitting sliding movement upon the cutters during the initial opening and subsequently supporting of the cutters by links from the head carried at the lower end of a sliding sleeve upon the drill rod.

The mere use of a wedge member alone will not expand the cutters sufliciently to effect the desired under-reaming for the formation of a chamber of material area at the bottom of the well, and my invention supplements this preliminary movement by means to shift the. cutters into a substantially horizontal posltion. 1

The invention has for an object to provide an under-reamer m which the stem 1s provided with expansible cutters and carries a movable sleeve having means to initiate the movement of the cutters and a connection from said sleeve to continue said movement for the full extent of the under-reaming action of the cutters.

.Af-urther object of the invention is to providea construction in which the drill stem tion with the cutters by which the links have a sliding movement upon the cutters in the initial wedging action thereon to throw the links from. a dead center and these remain in relatively fixed contact at one end of an elongated way to support the cutters in horizontal position. Such a construction permits the cutters to be closely nested when introduced into the well and to have the greatest area of expansion possible by the relative,

movement of the parts.

Other objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined by the appended claims.

In the accompanying drawing:

Figure 1 is an elevation showing the cutters in closed position;

Figure 2 is a section with the parts in similar position Figure 3 is a section showing the cutters partially open;

Figure 4 is a similar View with the cutters fully open and in position to excavate a chamber at" the base of the well;

Figure 5 is a section on line 55 of Figure 2;

Figure 6 member;

- Figure 7 is a section on the line 7 -7 of Figure 3; and

Figure 8 is a detail elevation showing the link connection with the cutters.

Like reference numerals designate correis a detail elevation of the sleeve sponding parts throughout the several figures of the drawing.

Theinvention is adapted for various applications, and in the form herein shown the drill stem 10 may be of any desired size or material and is formed at its lower endfwith a pivoting block 11 upon which the opposite cutters 12 are mounted by means of pivots 13 at each side of the axial center of the stem. These cutters or reamers may be of any desired type or configuration and are herein" shown in Figure as segmental in character so as to provide the greatest possible area and the adj acent faces 14 of such cutters are adapted to be closely aligned when the cutters are folded as shown ir Figure 2 so as to cause them to be closely nested within the diameter of the remaining parts of the reamer.

For the purpose of cooperating with the free ends of the cutters and initiating their expensive movement, the stem is provided with a sleeve 15 slidingly mounted thereon and held against rotative movement by a flat contact face,16 on the stem cooperating with a similar face of the sleeve as shown in Figure 7. The sleeve is formed with opposite depending braces 17 carrying at their lower ends a head 18 formed upon its upper surface with a wedge device, such asthe V- shaped walls 19, which cooperate with an inclined face 20 at the lower ends of the cutters.

As shown in Figure 3, when the head 18 engages the base of the well the continued movement of thereamer causes the wedge face 19 to effect an'initial outward movement of the cutters 12 which is continued by the links 21 connecting the head 18 and the cutters. By reference to Figure 2' it will be seen that when the cutters are in closed position these links are substantially parallel and this ini;

tial wedging movement is necessary to throw a the links off a dead center in order that the continued downward movement of the reamer will produce an upward movement of the cutters through the link action,

The links may be connected with the cutters and head in various manners, and a desirable form is shoivn in which the links are pivoted at 22 to opposite sides of the center of the head and provided at their upper ends with an elongated pin 23 which traverses the ways 24: formed in the cutters. This pin is of sufficiently less diameter than the ways to permit a slight rotative movement 'n the wedging action and in the'downward travel of the drill the pin 23 is moved into the enlarged portion 25 of the way at its end next the pivot of the cutter. When within said portion the pin is capable of a rotary movement necessary in the upward swing of the cutters and also is positioned at an angle to the length of the ways so as to retain it in the pivotal enlargements 25 when the cutters are approaching a horizontal position as shown in Figures 4 and 8. This arrangement prevents any movement of the link longitudinally of the elongated way after the reliminary wedging action has thrown the lin s into position for action;

If-it be desired to extend the operative field of the cutters when in expanded position to excavate the upper wall of a chamber, the head 18 may be provided with one or more steps 26 removably threaded into'an 'aperture 27 of the hea A convenient means for assembling the cutters is to provide them with an inner recess 28 adapted to receive the opposite links before described, and with an outer recess 29 within which the braces 17 are disposed, as this arrangement protects the links and permits a close assemblage of the several parts when in closed position.

The operation of. the invention will be apparent from the foregoing description and it will be seen that witlrthe cutters in the movement of the reanlers upon the wedge head of the sleeve which rsts upon the base of the well causes an initial opening as shown in Figure 3 which also separates the ends of the links connected to the cutters and positions them so that the continued downward movement causes the links to seat in the enlargement of the ways and force the cutters upward into a substantially horizontal position as shown in Figure 4 which also illustratesthe tyre of chamber formed at the base ofthewe l." v j y The invention therefore presents a construction by which a full expansive movement may be secured by the use of a link connection between 1 the head and cutters while these links may be closely folded in order to bring the cutters within the general diameter of the tool permitting its convenient introduction into the well before the reaming action is begun. By such an arrange- .ment the links being on a dead center practically lock the cutters against accidental displacement or engagement with the walls of the well or its casing and are thrown out of such locking position by the wedging action after the tool reaches the base of the well.

lVhile the details of construction have been shown and described, the invention is not confined thereto as changes and alterations may be made without departing from the spirit thereof as defined by the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. In an under-reamer, a stem provided with expansible cutters, a movable sleeve upon said stem provided with a wedge face position shown in Figure 2, thedownward to engage and initiate the opening movement of the cutters, and a pivoted link between said cutters and sleeve to continue such movesaid cutters and sleeve to continue such 1noveoted cutters carried thereb a sleeve slidable upon the stem, a heat carried by the sleeve and having an opening device actuating the free ends of the cutters, and links connecting said head and cutters intermediate their ends.

5. ln'an underreamer,.a drill stem, pivoted cutters carried thereby, a sleeve slidable upon the stem, ,a head carried by the sleeve and having an opening device disposed at the free ends of the cutters, andlinks pivoted upon the head and havinga sliding cond ll nection with the cutters.

6. In an under-reamer, a drill stem, pivoted cutters carried thereby, a' sleeve slid able upon the stem, at head carried by the sleeve and having an opening device disposed at the free ends of the'cutters, and links pivoted upon the head and having a sliding connection with elongated ways upon the cutters provided with enlarged head portions to permit pivotal movement of the link connection in the continued expansion of the cutters.

7. In an un'denreamer, a drill body, opposite cutters pivoted thereon, a sleeve mounted upon the drill body against rotation and formed with opposite depending braces, ahead supported by said braces beneath the free ends of the cutters,a wedge device carried by said head to engage such ends of. the cutters, and opposite links pivoted upon said head and formed with elongated pins adapted to traverse longitudinal ways in said outters and to rotate within an enlargement at the inner end of said ways.

8. In a reamer, a drill stem having a flattened face, a pivoting block at the lower end of said stein, opposite cutters mounted upon said block, a sleeve slidingly mounted upon the stem and provided with a fiat face to engage that of the stem, a head supported from said sleeve beneath the freeends of the cutters, an oppositely inclined wedge face upon said head adapted to engage the ends of the cutters, said cutters being provided withlongitudinal ways having enlarged pivoting chambers at their inner ends, and links pivoted upon the head and provided with pins elongated to prevent rotary movement in the ways but adapted to rotate within the pivoting chamber into position to prevent withdrawal therefrom when'the cutters are in substantially horizontal position 9. In an under-reamer, a drillstem, opposite segmental cutters Lpivoted thereon and provided with an interior recess and also with a recess at the end of each segmental face, a sleeve ,moun'ted upon the drill stem and provided with braces disposed within the outer. recesses of the cutters, a head carried by said braces, and links extending from said .head and connected to the cutters and dis posed within the inner recess of the cutters;

10. In an under-reamer, a support provided with expansible cutters, a movable member upon said support formed with means engaging the lower ends of the cutters to initiate .an opening mbvement of the'cutters, and a separate connection extending intermediate the ends of the cutters to said movable memberto continue the movement of the cutters out of contact with said means.

11. In an under-reamer, a support provided with expansible cutters, a movable member upon said support formed with means engaging the lower ends of the cutters to initiate an opening movement of thecutters, and a separate connection extending intermediate the ends of the cutters to'said movable member to continue the movement of the cutters out of contact with said means, such connection beingadapted to lock the ends of the cutters in closed position upon said means until released by the initial opening movement. p

In testimony whereof I aflix my signature.

WILLIAM P. RUDKIN. 

